Richard Needs: Publications

Hydrogen Clathrate Structures in Rare Earth Hydrides at High
Pressures: Possible Route to RoomTemperature Superconductivity,
Feng Peng, Ying Sun, Chris J. Pickard, Richard J. Needs, Qiang Wu,
and Yanming Ma,
Phys. Rev. Lett. 119, 107001 (2017)

Using forces to accelerate firstprinciples anharmonic vibrational calculations,
J. C. A. Prentice and R. J. Needs, Phys. Rev. Materials
1, 023801 (2017)

Shape and energy consistent pseudopotentials for correlated electron
systems
J. R. Trail and R. J. Needs, J. Chem. Phys.
146, 204107 (2017)

Ground state structure of highenergydensity polymeric carbon monoxide,
Kang Xia, Jian Sun, Chris J. Pickard, Dennis D. Klug,
and Richard J. Needs, Phys. Rev. B 95, 144102 (2017)

Quantum Monte Carlo study of the energetics of the rutile,
anatase, brookite, and columbite TiO2 polymorphs,
John Trail, Bartomeu Monserrat, Pablo Lopez Rios, Ryo Maezono,
and Richard J. Needs, Phys. Rev. B 95, 121108 (2017)

Energetics of H2 clusters from density functional and coupled
cluster theories
J. R. Trail, P. Lopez Rios, and
R. J. Needs, Phys. Rev. B 95, 115116 (2017)

Highpressure phases of groupII difluorides: Polymorphism and
superionicity
Joseph R. Nelson, Richard J. Needs,
and Chris J. Pickard, Phys. Rev. B 95, 054118 (2017)

Firstprinciples study of the dynamic JahnTeller distortion
of the neutral vacancy in diamond
J. C. A. Prentice,
B. Monserrat, and R. J. Needs, Phys. Rev. B 95, 014108 (2017)

TrailNeeds pseudopotentials in quantum Monte Carlo calculations with
planewave/blip basis sets
N. D. Drummond, J. R. Trail,
and R. J. Needs, Phys. Rev. B 94, 165170 (2016)

Hexagonal structure of phase III of solid hydrogen
Bartomeu Monserrat, Richard J. Needs, Eugene
Gregoryanz, and Chris J. Pickard, Phys. Rev. B 94, 134101
(2016)

Carbon Nitride Frameworks and Dense Crystalline Polymorphs
Chris J. Pickard, Ashkan Salamat, Michael
J. Bojdys, Richard J. Needs, and Paul F. McMillan,
Phys. Rev. B 94, 094104 (2016)

Report on the sixth blind test of organic crystal structure
prediction methods
A. M. Reilly et al., Acta
Cryst. 72, 439 (2016)
 Synthesis
of Sodium Polyhydrides at High Pressures
Viktor
V. Struzhkin, DuckYoung Kim, Elissaios Stavrou, Takaki Muramatsu,
Hokwang Mao, Chris J. Pickard, Richard J. Needs, Vitali
B. Prakapenka, and Alexander F. Goncharov, Nature
Communications 7, 12267 (2016)
 Vibrational
effects on surface energies and band gaps in hexagonal and cubic
ice
Edgar Engel, Bartomeu Monserrat, and Richard
J. Needs, J. Chem. Phys. 143, 044703 (2016)
 Trion
formation in a twodimensional holedoped electron gas
G. G. Spink, P. Lopez Rios, N. D. Drummond, and R. J. Needs,
Phys. Rev. B 94, 041410 (2016)
 Synthesis
and stability of xenon oxides Xe2O5 and Xe3O2 under pressure
Agnes Dewaele, Nicholas Worth, Chris J. Pickard,
Richard J. Needs, Sakura Pascarelli, Olivier Mathon, Mohamed
Mezouar, and Tetsuo Irifune
Nature Chemistry 8,
784 (2016)
 Perspective:
Role of structure prediction in materials discovery and
design
Richard J. Needs and Chris. J. Pickard
APL Materials 4, 053210 (2016)
 Quantum
hydrogenbond symmetrization in the superconducting hydrogen
sulfide system
Ion Errea, Matteo Calandra, Chris
J. Pickard, Joseph R. Nelson, Richard J. Needs, Yinwei Li, Hanyu
Liu, Yunwei Zhang, Yanming Ma, and Francesco Mauri
Nature 532, 81 (2016)

Pseudopotential for the twodimensional contact interaction
T. M. Whitehead, L. M. Schonenberg, N. Kongsuwan,
Richard. J. Needs, and G. J. Conduit
Phys. Rev. A 93,
042702 (2016)

Highpressure phase stability and superconductivity of pnictogen
hydrides and chemical trends for compressed hydrides
Yuhao Fu, Du Xiangpo, Lijun Zhang, Feng Peng, Miao
Zhang, Chris Pickard, Richard Needs, David Singh, Weitao Zheng, and
Yanming Ma
Chem. Mater. 28, 1746 (2016)

Dissociation products and structures of solid H2S at strong compression
Yinwei Li, Lin Wang, Hanyu Liu, Yunwei Zhang, Jian Hao, Chris
J. Pickard, Joseph R. Nelson, Richard J. Needs, Wentao Li,
Yanwei Huang, Ion Errea, Matteo Calandra, Francesco Mauri, and
Yanming Ma, Phys. Rev. B 93, 020103 (2016)

Vibrational renormalisation of the electronic band gap in hexagonal and cubic ice
Edgar A. Engel, Bartomeu Monserrat, and Richard J. Needs
J. Chem. Phys. 143, 244708 (2015)

Giant electronphonon interactions in molecular crystals and the
importance of nonquadratic coupling
Bartomeu Monserrat, Edgar A. Engel, and Richard
J. Needs
Phys. Rev. B 92, 140302 (2015)

Computational searches for iron oxides at high pressures
Gihan L. Weerasinghe, Chris J. Pickard, and R. J. Needs,
Journal of Physics: Condensed Matter 27, 45 (2015)

Pseudopotential for the electronelectron interaction
Jonathan H. LloydWilliams, R. J. Needs, and G. J. Conduit,
Phys. Rev. B 92, 075106 (2015)

Quantum Monte Carlo study of the phase diagram of solid molecular hydrogen at extreme
pressures
N. D. Drummond, Bartomeu Monserrat, Jonathan H. LloydWilliams,
Chris. J. Pickard, P. Lopez Rios, and Richard J. Needs,
Nature Communications 6,
7794 (2015)

Anharmonic nuclear motion and the relative stability of hexagonal and cubic ice
Edgar A. Engel, Bartomeu Monserrat, and Richard J. Needs,
Phys. Rev. X 5, 021033 (2015)

Lowenergy tetrahedral polymorphs of carbon, silicon, and germanium
Andres Mujica, Chris J. Pickard, and Richard J. Needs,
Phys. Rev. B 91, 214104 (2015)

Highpressure hydrogen sulfide from first principles: a stronglyanharmonic
phononmediated superconductor
Ion Errea, Matteo Calandra, Chris J. Pickard,
Joseph Nelson, Richard J. Needs,
Yinwei Li, Hanyu Liu, Yunwei Zhang, Yanming Ma, and
Francesco Mauri
Phys. Rev. Lett. 114, 15704 (2015)

Prediction of 10fold coordinated TiO2 and SiO2 structures at multimegabar pressures
Matthew J. Lyle, Chris J. Pickard, and Richard J. Needs
Proc. Natl. Acad. Sci. USA 112, 6898 (2015)

Metallic Icosahedron Phase of Sodium at Terapascal Pressures
Yinwei Li, Yanchao Wang, Chris J. Pickard, Richard J. Needs,
Yi Wang, and Yanming Ma
Phys. Rev. Lett. 114, 5501 (2015)

Calcium peroxide from ambient to high pressures
Joseph R. Nelson, Richard J. Needs, and Chris J. Pickard
Phys. Chem. Chem. Phys. 17, 6889 (2015)

Structures and stability of calcium and magnesium carbonates at mantle pressures
Chris J. Pickard and Richard J. Needs
Phys. Rev. B 91, 104101 (2015)

Correlated electron pseudopotentials for 3dtransition metals
John Trail and Richard J. Needs
J. Chem. Phys. B 142, 064110 (2015)

Extracting semiconductor band gap zeropoint corrections from experimental data
Bartomeu Monserrat, G. J. Conduit, and R. J. Needs
Phys. Rev. B 90, 042501 (2014)

Temperature effects in firstprinciples solid state calculations
of the chemical shielding tensor made simple
Bartomeu Monserrat, Richard J. Needs, and Chris J. Pickard
J. Chem. Phys. 141, 134113 (2014)

Exact and approximate KohnSham potentials in ensemble
densityfunctional theory
Zenghui Yang, John R.
Trail, Aurora PribramJones, Kieron Burke, Richard J. Needs, and
Carsten A. Ullrich
Phys. Rev. A 90, 042501 (2014)

Highfidelity pseudopotentials for the contact
interaction
P. O. Bugnion, P. Lopez Rios, R. J. Needs, and G. J. Conduit
Phys. Rev. A 90, 033626 (2014)

Piling up the pressure
Chris J. Pickard and
Richard J. Needs
Nature News and Views 511, 294
(2014)

Comparing electronphonon coupling strength in diamond, silicon,
and silicon carbide: Firstprinciples study
Bartomeu Monserrat and R. J. Needs
Phys. Rev. B 89,
214304 (2014)

Experimental and theoretical evidence for an ionic crystal of
ammonia at high pressure
S. Ninet, F. Datchi,
P. Dumas, M. Mezouar, G. Garbarino, A. Mafety, C. J. Pickard,
R. J. Needs, and A. M. Saitta
Phys. Rev. B 89,
174103 (2014)

Excitations and benchmark ensemble density functional theory for
two electrons
Aurora PribramJones, Zenghui Yang,
John R. Trail, Kieron Burke, Richard J. Needs, and Carsten
A. Ullrich
J. Chem. Phys. 140, 18A541 (2014)

Comparison of Smooth HartreeFock Pseudopotentials
J. R. Trail and R. J. Needs
J. Chem. Theory
Comput. 10, 2049 (2014)

Dissociation of highpressure solid molecular hydrogen: a quantum
Monte Carlo and anharmonic vibrational study
Sam
Azadi, Bartomeu Monserrat, W. M. C. Foulkes, and R. J. Needs
Phys. Rev. Lett. 112, 165501 (2014)

Quantum Monte Carlo and highlevel ab initio molecular orbital
investigation of dissociation channels of the positronic
alkalimetal hydrides, [XH;e+] (X = Li, Na, and K)
Yurika Yamada, Yukiumi Kita, Masanori Tachikawa, Mike D. Towler,
and Richard J. Needs
Eur. Phys. J. D 68, 63 (2014)

Compression algorithm for multideterminant wave
functions
Gihan L. Weerasinghe, Pablo Lopez Rios,
and Richard J. Needs
Phys. Rev. E 89, 023304 (2014)

ElectronPhonon Coupling and the Metalization of Solid Helium at
Terapascal Pressures
Bartomeu Monserrat, N. D. Drummond, Chris
J. Pickard, and R. J. Needs
Phys. Rev. Lett. 112,
055504 (2014)

Anomalous nonadditive dispersion interactions in systems of
three onedimensional wires
Alston J. Misquitta,
Ryo Maezono, Neil D. Drummond, Anthony J. Stone, and Richard
J. Needs
Phys. Rev. B 89, 045140 (2014)

Quantum Monte Carlo studies of 13atom simple metallic
clusters
C.R. Hsing, P. Lopez Rios, R.J. Needs,
and C.M. Wei
Phys. Rev. B 88, 165412 (2013)

Stable allnitrogen metallic salt at terapascal pressures
Jian Sun, Miguel MartinezCanales, Dennis
D. Klug, Chris J. Pickard, and Richard J. Needs
Phys. Rev. Lett. 111, 175502 (2013)

Quantum Monte Carlo study of the threedimensional
spinpolarized homogeneous electron gas
G.G. Spink, R.J. Needs and N.D. Drummond
Phys. Rev. B 88, 085121 (2013)

Quantum Monte Carlo calculation of the Fermi liquid parameters
of the twodimensional homogeneous electron gas
N.D. Drummond and R.J. Needs
Phys. Rev. B 88,
035133 (2013)

Quantum simulation of lowtemperature metallic liquid
hydrogen
Ji Chen, XinZheng Li, Qianfan Zhang,
Matthew I. J. Probert, Chris J. Pickard, Richard J. Needs,
Angelos Michaelides, and Enge Wang
Nature
Communications 4, 2064 (2013)

Pseudopotentials for correlated electron systems
J.R. Trail and R.J. Needs
J. Chem. Phys. 139, 014101 (2013)

Decomposition and terapascal phases of water ice
C.J. Pickard, M. MartinezCanales, and R.J. Needs
Phys. Rev. Lett. 110, 245701 (2013)

Excitons and biexcitons in symmetric electronhole
bilayers
Ryo Maezono, Pablo Lopez Rios, Tetsuo
Ogawa, and R.J. Needs
Phys. Rev. Lett. 110, 216407
(2013)

Lithiation of silicon anodes via lithium Zintldefect
complexes
A.J. Morris, R.J. Needs, E. Salager,
C.P. Grey, and C.J. Pickard
Phys. Rev. B 87, 174108
(2013)

Anharmonic vibrational properties in periodic systems: energy,
electronphonon coupling, and stress
Bartomeu
Monserrat, N.D. Drummond, and R.J. Needs
Phys. Rev. B 87, 144302 (2013)

Diffusion quantum Monte Carlo calculation of the quasiparticle
effective mass of the twodimensional homogeneous electron
gas
N.D. Drummond and R.J. Needs
Phys. Rev. B 87, 045131 (2013)

Classical and quantum ordering of protons in cold solid hydrogen
under megabar pressures
XinZheng Li, Brent Walker, Matthew I. J. Probert, Chris J. Pickard,
Richard J. Needs, and Angelos Michaelides
J. Phys.: Condensed
Matter 25, 085402 (2013)

Framework for constructing generic Jastrow correlation
factors
P. Lopez Rios, P. Seth, N.D. Drummond, and
R.J. Needs
Phys. Rev. E 86, 036703 (2012)

Highpressure ionic and molecular phases of ammonia within
density functional theory
G.I.G. Griffiths,
R.J. Needs, and C.J. Pickard
Phys. Rev. B 86, 144102 (2012)

Phase stability and superconductivity of strontium under
pressure
D.Y. Kim, P. Srepusharawoot, C.J. Pickard,
R.J. Needs, T. Bovornratanaraks, R. Ahuja, and U. Pinsook
Appl. Phys. Lett. 101, 052604 (2012)

High pressure ionic and molecular crystals of ammonia
monohydrate within density functional theory
G.I.G. Griffiths, A.J. Misquitta, A.D. Fortes, C.J. Pickard, and
R.J. Needs
J. Chem. Phys. 137, 064506 (2012)

Density functional theory study of phase IV of solid
hydrogen
C.J. Pickard, M. MartinezCanales, and
R.J. Needs
Phys. Rev. B 85, 214114 (2012)

Crystal Structure of Ammonia Dihydrate II
G.I.G. Griffiths, A.D. Fortes, C.J. Pickard, and R.J. Needs
J. Chem. Phys. 136, 174512 (2012)

Thermodynamically stable phases of carbon at multiterapascal pressures
M. MartinezCanales, C.J. Pickard, and R.J. Needs
Phys. Rev. Lett. 108, 045704 (2012)

Persistence and eventual demise of oxygen molecules at
terapascal pressures
J. Sun, M. MartinezCanales,
D.D. Klug, C.J. Pickard, and R.J. Needs
Phys. Rev. Lett. 108, 045503 (2012)

Energetics of hydrogen/lithium complexes in silicon analyzed
using the Maxwell construction
A.J. Morris,
C.P. Grey, R.J. Needs, and C.J. Pickard
Phys. Rev. B 84, 224106 (2011)

Towards crystal structure prediction of complex organic
compounds  a report on the fifth blind test
D.A. Bardwell, C.S. Adjiman, Y.A. Arnautova, E. Bartashevich,
S.X.M. Boerrigter, D.E. Braun, A.J. CruzCabeza, G.M. Day,
R.G. Della Valle, G. R. Desiraju, B.P. van Eijck, J.C. Facelli,
M.B. Ferraro, D. Grillo, M. Habgood, D.W.M. Hofmann, F. Hofmann,
K.V. Jovan Jose, P.G. Karamertzanis, A.V. Kazantsev,
J. Kendrick, L.N. Kuleshova, F.J.J. Leusen, A.V. Maleev,
A.J. Misquitta, S. Mohamed, R.J. Needs, M.A. Neumann,
D. Nikylov, A.M. Orendt, R. Pal, C.C. Pantelides, C.J. Pickard,
L.S. Price, S.L. Price, H.A. Scheraga, J. van de Streek,
T.S. Thakur, S. Tiwari, E. Venuti, and I.K. Zhitkov
Acta Crystallographica B 67, 535 (2011)

Computational searches for iron carbide in the Earth's inner core
G.L. Weerasinghe, R.J. Needs, and C.J. Pickard
Phys. Rev. B 84, 174110 (2011)

Quantum Monte Carlo study of a positron in an electron gas
N.D. Drummond, P. Lopez Rios, R.J. Needs, and
C.J. Pickard
Phys. Rev. Lett. 107, 207402 (2011)

Theoretical investigation of xenonhydrogen solids under
pressure using abinitio DFT and GW calculations
T. Kaewmaraya, D.Y. Kim, S. Lebegue, C.J. Pickard,
R.J. Needs, and R. Ahuja
Phys. Rev. B 84, 092101 (2011)

Predicted formation of superconducting platinumhydride crystals
under pressure in the presence of molecular hydrogen
D.Y. Kim, R.H. Scheicher, C.J. Pickard,
R.J. Needs, and R. Ahuja
Phys. Rev. Lett. 107, 117002
(2011)

Predicted pressureinduced sband ferromagnetism in alkali
metals
C.J. Pickard and R.J. Needs
Phys. Rev. Lett. 107, 087201 (2011)
 Ab
initio quantum Monte Carlo study of the binding of a positron to
alkalimetal hydrides
Y. Kita, R. Maezono,
M. Tachikawa, M.D. Towler, and R.J. Needs
J. Chem. Phys. 135, 054108 (2011)

Quantum Monte Carlo calculation of the zerotemperature phase
diagram of the twocomponent fermionic hardcore gas in two
dimensions
N.D. Drummond, N.R. Cooper,
R.J. Needs, and G.V. Shlyapnikov
Phys. Rev. B 83,
195429 (2011)

Controlling the Bonding and Band Gaps of Solid Carbon Monoxide
with Pressure
J. Sun, D.D. Klug, C.J. Pickard,
and R.J. Needs
Phys. Rev. Lett. 106, 145502 (2011)

Theoretical study of pressuredriven phase transitions in HgSe
and HgTe
S. Radescu, A. Mujica, J. LopezSolano,
and R.J. Needs
Phys. Rev. B 83, 094107 (2011)

Quantum Monte Carlo study of the firstrow atoms and ions
P. Seth, P. Lopez Rios, and R.J. Needs
J. Chem. Phys. 134, 084105 (2011)

Ab initio Random Structure Searching
C.J. Pickard and R.J. Needs
J. Phys.: Condensed
Matter 23, 053201 (2011)

Diamond to betatin phase transition in Si within diffusion
quantum Monte Carlo
R. Maezono, N.D. Drummond,
A. Ma, and R.J. Needs
Phys. Rev. B 82, 184108 (2010)

Dopingdriven magnetic instabilities and quantum criticality of
NbFe_{2}
D.A. Tompsett, R.J. Needs,
F.M. Grosche, and G.G. Lonzarich
Phys. Rev. B 82,
155137 (2010)

A variational Monte Carlo study of positronic compounds using
inhomogeneous backflow transformations
Y. Kita,
M. Tachikawa, N.D. Drummond, and R.J. Needs
Chem. Lett. 39, 1136 (2010)

Aluminium at terapascal pressures
C.J. Pickard and R.J. Needs
Nature Materials 9, 624
(2010)

Firstprinciples method for impurities in quantum fluids:
Positron in an electron gas
N.D. Drummond,
P. Lopez Rios, C.J. Pickard and R.J. Needs
Phys. Rev. B 82, 035107 (2010)

Quantum Monte Carlo computations of phase stability, equations
of state, and elasticity of highpressure silica
K.P. Driver, R.E. Cohen, Z. Wu, B. Militzer, P. Lopez Rios,
M.D. Towler, R.J. Needs and J.W. Wilkins
Proc. Natl. Acad. Sci. USA 107, 9519 (2010)

Fundamental highpressure scale from allelectron quantum Monte
Carlo calculations
K.P. Esler, R.E. Cohen, B. Militzer,
J. Kim, R.J. Needs and M.D. Towler
Phys. Rev. Lett. 104,
185702 (2010)

Ultracold atoms at unitarity within quantum Monte
Carlo
A.J. Morris, P. Lopez Rios and
R.J. Needs
Phys. Rev. A 81, 033619 (2010)

Methods for calculating forces within quantum Monte
Carlo
A. Badinski, P.D. Haynes, J.R. Trail,
and R.J. Needs
J. Phys.: Condensed Matter 22, 074202 (2010)

Benchmark ab initio quantum Monte Carlo calculations on small
molecules using Slater and Gaussian basis sets
N. Nemec, M.D. Towler and R.J. Needs
J. Chem. Phys. 132, 034111 (2010)

Hypothetical lowenergy chiral framework structure of group 14
elements
C.J. Pickard and R.J. Needs
Phys. Rev. B 81, 014106 (2010)

Continuum variational and diffusion quantum Monte Carlo
calculations
R.J. Needs, M.D. Towler,
N.D. Drummond and P. Lopez Rios
J. Phys.: Condensed
Matter 22, 023201 (2010)

Quantum Monte Carlo Calculation of the Energy Band and
Quasiparticle Effective Mass of the TwoDimensional Fermi
Fluid
N.D. Drummond and R.J. Needs
Phys. Rev. B 80, 245104 (2009)

Postcotunnite phase of TeO_{2} obtained from
firstprinciples densityfunctional theory methods with
randomstructure searching
G.I.G. Griffiths,
R.J. Needs, and C.J. Pickard
Phys. Rev. B 80, 184115
(2009)

Hydrogen/nitrogen/oxygen defect complexes in silicon from
computational searches
A.J. Morris, C.J.
Pickard, and R.J. Needs
Phys. Rev. B 80, 144112
(2009)

Softphonon instability in zincblende HgSe and HgTe under
moderate pressure: Ab initio pseudopotential
calculations
S. Radescu, A. Mujica, and
R.J. Needs
Phys. Rev. B 80, 144110 (2009)

Stable phases of iron at terapascal pressures
C.J. Pickard, and R.J. Needs
J. Phys.: Condensed
Matter 21, 452205 (2009)
 Equation
of state and phase transition of deuterated ammonia monohydrate
(ND_{3}·D_{2}O) measured by highresolution
neutron powder diffraction up to 500 MPa
A.D.
Fortes, E. Suard, M.H. LemeeCailleau, C.J. Pickard, and
R.J. Needs
J. Chem. Phys. 131, 154503 (2009)
 Ab
initio quantum Monte Carlo study of the positronic hydrogen
cyanide molecule
Y. Kita, R. Maezono, M.
Tachikawa, M. Towler, and R.J. Needs
J. Chem. Phys. 131, 134310 (2009)

Crystal structure of ammonia monohydrate phase II
A.D.
Fortes, E. Suard, M.H. LemeeCailleau, C.J. Pickard, and
R.J. Needs
J. Am. Chem. Soc. 131, 13508 (2009)

Quantum Monte Carlo studies of covalent and metallic clusters:
Accuracy of density functional approximations
C.R. Hsing, C.M. Wei, N.D. Drummond, and R.J. Needs
Phys. Rev. B 79, 245401 (2009)

Dense lowcoordination phases of lithium
C.J. Pickard and R.J. Needs
Phys. Rev. Lett. 102,
146401 (2009)

HighPressure Phases of Nitrogen
C.J. Pickard and
R.J. Needs
Phys. Rev. Lett. 102, 125702 (2009)

Phase Diagram of the LowDensity TwoDimensional Homogeneous
Electron Gas
N.D. Drummond and R.J. Needs
Phys. Rev. Lett. 102, 126402 (2009)

Excitonexciton interaction and biexciton formation in bilayer
systems
R.M. Lee, N.D. Drummond, and
R.J. Needs
Phys. Rev. B 79, 125308 (2009)

Quantum Monte Carlo study of the ground state of the
twodimensional Fermi fluid
N.D. Drummond and
R.J. Needs
Phys. Rev. B 79, 085414 (2009)

Structures at high pressure from random searching
C.J. Pickard and R.J. Needs
Physica Status Solidi (b)
246, 536 (2009)
 Energy
derivatives in quantum Monte Carlo involving the zerovariance
property
A. Badinski, J.R. Trail, and
R.J. Needs
J. Chem. Phys. 129, 224101 (2008)

Hydrogen/silicon complexes in silicon from computational
searches
A.J. Morris, C.J. Pickard, and
R.J. Needs
Phys. Rev. B 78, 184102 (2008)

Highly compressed ammonia forms an ionic crystal
C.J. Pickard and R.J. Needs
Nature Materials 7, 775
(2008)

Finitesize errors in continuum quantum Monte Carlo calculations
N.D. Drummond, R.J. Needs, A. Sorouri, and
W.M.C. Foulkes
Phys. Rev. B 78, 125106 (2008)

Quantum Monte Carlo study of porphyrin transition metal complexes
Jun Koseki, Ryo Maezono, Masanori Tachikawa,
M.D. Towler, and R.J. Needs
J. Chem. Phys. 129,
085103 (2008)

Total forces in the diffusion Monte Carlo method with nonlocal
pseudopotentials
A. Badinski and R.J. Needs
Phys. Rev. B 78, 035134 (2008)

Spectroscopic data for the LiH molecule from pseudopotential
quantum Monte Carlo calculations
J.R. Trail and R.J. Needs
J. Chem. Phys. 128, 204103 (2008)

Nodal Pulay Terms for Accurate Diffusion Quantum Monte Carlo Forces
A. Badinski, P.D. Haynes, and R.J. Needs
Phys. Rev. B 77, 085111 (2008)

When is H_{2}O not water?
C.J. Pickard and R.J. Needs
J. Chem. Phys. 127, 244503 (2007)

Metallization of aluminum hydride at high pressures:
A firstprinciples study
C.J. Pickard and R.J. Needs
Phys. Rev. B 76, 144114 (2007)

van der Waals Interactions between Thin Metallic Wires and Layers
N.D. Drummond and R.J. Needs
Phys. Rev. Lett. 99, 166401 (2007)

Dissociation energy of the water dimer from Quantum Monte Carlo
calculations
I.G. Gurtubay and R.J. Needs
J. Chem. Phys. 127, 124306 (2007)
 Accurate
forces in Quantum Monte Carlo calculations with nonlocal
pseudopotentials
A. Badinski and R.J. Needs
Phys. Rev. E 76, 036707 (2007)
 Energies
of the first row atoms from quantum Monte Carlo
M.D. Brown, J.R. Trail, P. Lopez Rios, and R.J. Needs
J. Chem. Phys. 126, 064301 (2007)

Structure of phase III of solid hydrogen
C.J. Pickard
and R.J. Needs
Nature Physics 3, 473 (2007)

Fragmentation method combined with Quantum Monte Carlo
calculations
Ryo Maezono, Hirofumi Watanabe,
Shigenori Tanaka, M.D. Towler, and R.J. Needs
Journal of the Physical Society of Japan 76, 064301 (2007)

Graphite intercalation compounds under pressure
Gabor Csanyi, Chris J. Pickard, B.D. Simons, and R.J. Needs
Phys. Rev. B 75, 085432 (2007)

Equation of state and Raman frequency of diamond from quantum
Monte Carlo simulations
Ryo Maezono, A. Ma,
M.D. Towler, and R.J. Needs
Phys. Rev. Lett. 98, 025701
(2007)

DMC Study of the Optoelectronic Properties of Diamondoids
N. Drummond, A. Williamson, R.J. Needs, and G. Galli
Mater. Res. Soc. Symp. Proc. 958, 0958L0904 (2007)

Inhomogeneous backflow transformations in Quantum Monte
Carlo
P. Lopez Rios, A. Ma, N.D. Drummond,
M.D. Towler, and R.J. Needs
Phys. Rev. E 74, 066701
(2006)

Quantum Monte Carlo calculations of the dissociation energy of
the water dimer
N.A. Benedek, I.K. Snook,
M.D. Towler, and R.J. Needs
J. Chem. Phys. 125,
104302 (2006)

Highpressure phases of silane
C.J. Pickard and
R.J. Needs
Phys. Rev. Lett.
97, 045504 (2006)

Quantum Monte Carlo study of the Ne atom and the Ne^{+}
ion
N.D. Drummond, P. Lopez Rios, A. Ma,
J.R. Trail, G. Spink, M.D. Towler, and R.J. Needs
J. Chem. Phys.
124, 224104 (2006)

Quantum Monte Carlo, DensityFunctional Theory, and
PairPotential Studies of Solid Neon
N.D. Drummond
and R.J. Needs
Phys. Rev. B
73, 024107 (2006)

Quantum Monte Carlo calculations of the dissociation energies of
threeelectron hemibonded radical cationic dimers
I.G. Gurtubay, N.D. Drummond, M.D. Towler, and R.J. Needs
J. Chem. Phys. 124, 024318 (2006)
 Quantum Monte Carlo Techniques and Defects in Semiconductors
R.J. Needs
in "Theory of Defects in Semiconductors"
(Springer Verlag, Berlin, Heidelberg) Eds. D.A. Drabold and
S.K. Estreicher, Topics Appl. Physics 104, 141 (2006)

Varianceminimization scheme for optimizing Jastrow factors
N.D. Drummond and R.J. Needs
Phys. Rev. B
72, 085124 (2005)

Quantum Monte Carlo calculations of the structural properties
and the B1B2 phase transition of MgO
D. Alfè,
M. Alfredsson, J. Brodholt, M.J. Gillan, M.D. Towler, and
R.J. Needs
Phys. Rev. B 72, 014114 (2005)

Allelectron quantum Monte Carlo calculations for the noble gas
atoms He to Xe
A. Ma, N.D. Drummond, M.D. Towler, and
R.J. Needs
Phys. Rev. E 71, 066704 (2005)

Electron Emission from Diamondoids: A Diffusion Quantum Monte
Carlo Study
N.D. Drummond, A.J. Williamson,
R.J. Needs, and G. Galli
Phys. Rev. Lett. 95, 096801
(2005)

Scheme for adding electronnucleus cusps to Gaussian orbitals
A. Ma, M.D. Towler, N.D. Drummond, and R.J. Needs
J. Chem. Phys. 122, 224322 (2005)

Smooth Relativistic HartreeFock Pseudopotentials for H to Ba
and Lu to Hg
J.R. Trail and R.J. Needs
J. Chem. Phys. 122, 174109 (2005)

NormConserving HartreeFock Pseudopotentials and their
Asymptotic Behaviour
J.R. Trail and R.J. Needs
J. Chem. Phys. 122, 014112 (2005)

Exciton and biexciton energies in bilayer systems
M.Y.J. Tan, N.D. Drummond and R.J. Needs
Phys. Rev. B
71, 033303 (2005)

Jastrow correlation factor for atoms, molecules, and solids
N.D. Drummond, M.D. Towler, and R.J. Needs
Phys. Rev. B 70, 235119 (2004)

Diamond and betatin structures of Si studied with quantum Monte
Carlo calculations
D. Alfè, M.J. Gillan, M.D. Towler,
and R.J. Needs
Phys. Rev. B 70, 214102 (2004)

Interpretation of Hund's multiplicity rule for the carbon atom
Kenta Hongo, Ryo Maezono, Yoshiyuki Kawazoe, Hiroshi
Yasuhara, M.D. Towler, and R.J. Needs
J. Chem. Phys. 121, 7144 (2004)

Structural relaxations in electronically excited
poly(paraphenylene)
Emilio Artacho,
M. Rohlfing, M. Cote, P.D. Haynes, R.J. Needs, and
C. Molteni
Phys. Rev. Lett. 93, 116401 (2004)

Diffusion quantum Monte Carlo study of threedimensional Wigner
crystals
N.D. Drummond, Z. Radnai, J.R. Trail,
M.D. Towler, and R.J. Needs
Phys. Rev. B 69, 085116
(2004)

Spectral Moments in the Homogeneous Electron Gas
M. Vogt, R. Zimmermann, and R.J. Needs
Phys. Rev. B
69, 045113 (2004)

Free energy calculations of intrinsic point defects in silicon
Omar AlMushadani and R.J. Needs
Phys. Rev. B
68, 235205 (2003)

Quantum Monte Carlo study of the optical and diffusive
properties of the vacancy defect in diamond
R.Q. Hood,
P.R.C. Kent, R.J. Needs, and P.R. Briddon
Phys. Rev. Lett. 91, 076403 (2003)

Stability and aromaticity of B_{i}N_{i} rings
and fullerenes
Jon M. Matxain, Jesus M. Ugalde,
M.D. Towler, and R.J. Needs
J. Phys. Chem. A 107,
10004 (2003)

Quantum Monte Carlo investigations of density functional theory
of the strongly inhomogeneous electron gas
M. Nekovee,
W.M.C. Foulkes, and R.J. Needs
Phys. Rev. B 68, 235108 (2003)

Quantum Monte Carlo study of sodium
Ryo Maezono,
M.D. Towler, Y. Lee, R.J. Needs
Phys. Rev. B 68,
165103 (2003)

Unrestricted HartreeFock Theory of Wigner Crystals
J.R. Trail, M.D. Towler, and R.J. Needs
Phys. Rev. B
68, 045107 (2003)

High pressure phases of group IVa, IIIaVa, and IIbVIa
compounds
A. Mujica, A. Rubio, A. Munoz, and
R.J. Needs
Rev. Mod. Phys. 75, 863 (2003)

CorePolarization Potentials for Si and Ti
Y. Lee
and R.J. Needs
Phys. Rev. B 67, 035121 (2003)

Quantum Monte Carlo Studies of Density Functional Theory
M. Nekovee, W.M.C. Foulkes, and R.J. Needs
Mathematics and Computers in Simulation 62, 463 (2003)

The diffusion quantum Monte Carlo method: designing trial
wave functions for NiO
R.J. Needs and
M.D. Towler
Int. J. Mod. Phys. B 17, 5425 (2003)
 Quantum Monte Carlo Calculations of the Pair Correlation
Functions of Jellium
W.K. Leung and R.J. Needs
in
"Computational Methods in Engineering and Science",
Proceedings of the Ninth International Conference on Enhancement
and Promotion of Computational Methods in Engineering and
Science,
Macao 2003, Eds. V.P. Iu, L. N. Lamas, Y.P. Li, and
K.M. Mok, p. 829832 (Swets and Zeitlinger, Lisse) 2003
 Quantum Monte Carlo Study of the Relativistic SpinPolarized
Jellium
W.K. Leung and R.J. Needs
in "Computational
Methods in Engineering and Science",
Proceedings of the Ninth
International Conference on Enhancement and Promotion of
Computational Methods in Engineering and Science,
Macao 2003,
Eds. V.P. Iu, L.N. Lamas, Y.P. Li, and K.M. Mok, p. 833838
(Swets and Zeitlinger, Lisse) 2003
 The CASINO program: quantum Monte Carlo in molecular quantum
chemistry and condensed matter physics
M.D. Towler and
R.J. Needs
Quantum Monte Carlo: Recent Advances and Common
Problems in Condensed Matter and Field Theory (ETS, Pisa),
p. 129 (2002)
 Quantum Monte Carlo Calculations for Excited Electronic
States
R.J. Needs, A.R. Porter, and M.D. Towler
Recent advances in quantum Monte Carlo Methods, Part
II,
Eds. W.A. Lester, Jr., S.M. Rothstein, and S. Tanaka,
p. 143 (World Scientific, Singapore) 2002

Highpressure behaviour of Si and Ge: A theoretical study
A. Mujica, S. Radescu, A. Munoz, and R.J. Needs
High Pressure Research 22, 455 (2002)

Theoretical description of highpressure phases of
semiconductors
R.J. Needs and A. Mujica
High
Pressure Research 22, 421 (2002)

Electronic structure of ptype conducting transparent
oxides
J. Robertson, P.W. Peacock, M.D. Towler,
and R.J. Needs
Thin Solid Films 411, 96 (2002)
 Quantum Monte
Carlo Calculations for Ground and Excited States
R.J. Needs, P.R.C. Kent, A.R. Porter, M.D. Towler, and
G. Rajagopal
Int. J. Quant. Chem. 86, 218 (2002)

Quantum Monte Carlo Analysis of Exchange and Correlation in the
Strongly Inhomogeneous Electron Gas
M. Nekovee,
W.M.C. Foulkes, and R.J. Needs
Phys. Rev. Lett. 87,
036401 (2001)

Excitons in Small Hydrogenated Si Clusters
A.R. Porter, M.D. Towler, and R.J. Needs
Phys. Rev. B
64, 035320 (2001)

Excitons in Tshaped quantum wires
M.H. Szymanska,
P.B. Littlewood, and R.J. Needs
Phys. Rev. B 63,
205317 (2001)

Electronic excitedstate wave functions for quantum Monte Carlo:
Application to silane and methane
A.R. Porter,
O.K. AlMushadani, M.D. Towler, and R.J. Needs
J. Chem. Phys. 114, 7795 (2001)

Inhomogeneous Random Phase Approximation and ManyElectron Trial
Wave Functions
R. Gaudoin, M. Nekovee,
W.M.C. Foulkes, R.J. Needs, and G. Rajagopal
Phys. Rev. B
63, 115115 (2001)

Highpressure phases of germanium
A. Mujica,
S. Radescu, A. Munoz, and R.J. Needs
J. Phys.: Condensed
Matter 13, 35 (2001)

Quantum Monte Carlo simulations of Solids
W.M.C. Foulkes, L. Mitas, R.J. Needs, and G. Rajagopal
Rev. Mod. Phys. 73, 33 (2001)

Comparative study of novel structures in silicon and
germanium
A. Mujica, S. Radescu, A. Munoz, and
R.J. Needs
Physica Status Solidi (b) 223, 379 (2001)

Carbon clusters near the crossover to fullerene stability
P.R.C. Kent, M.D. Towler, R.J. Needs, and
G. Rajagopal
Phys. Rev. B 62, 15394 (2000)

Pseudopotentials for CorrelatedElectron Calculations
Y. Lee, P.R.C. Kent, M.D. Towler, R.J. Needs, and
G. Rajagopal
Phys. Rev. B 62, 13347 (2000)

Minimum principles and level splitting in quantum Monte Carlo
excitation energies: application to diamond
M.D. Towler, Randolph Q. Hood, and R.J. Needs
Phys. Rev. B
62, 2330 (2000)

Comment on "Quantum Monte Carlo study of the dipole moment of
CO" [J. Chem. Phys. 110, 11700 (1999)]
K.C. Huang,
R.J. Needs, and G. Rajagopal
J. Chem. Phys. 112, 4419
(2000)

Firstprinciples calculations of selfinterstitial defect
structures and diffusion paths in silicon
R.J. Needs
J. Phys.: Condensed Matter 11, 10437 (1999)

Muonium as a hydrogen analogue in silicon and germanium; quantum
effects and hyperfine parameters
A.R. Porter,
M.D. Towler, and R.J. Needs
Phys. Rev. B 60, 13534
(1999)

Calculations of Silicon SelfInterstitial Defects
W.K. Leung, R.J. Needs, G. Rajagopal, S. Itoh, and S. Ihara
Phys. Rev. Lett. 83, 2351 (1999)

Symmetry Constraints and Diffusion Quantum Monte Carlo
Calculations of ExcitedState Energies
W.M.C. Foulkes, R.Q. Hood, and R.J. Needs
Phys. Rev. B
60, 4558 (1999)

Monte Carlo energy and variance minimization techniques for
optimizing manybody wave functions
P.R.C. Kent,
R.J. Needs, and G. Rajagopal
Phys. Rev. B 59, 12344
(1999)

Finite size errors in quantum manybody simulations of extended
systems
P.R.C. Kent, R.Q. Hood, A.J. Williamson,
R.J. Needs, W.M.C. Foulkes, and G. Rajagopal
Phys. Rev. B
59, 1917 (1999)
 AlX
(X = As, P, Sb) compounds under pressure
A. Mujica, P. RodriguezHernandez, S. Radescu, R.J. Needs, and
A. Munoz
Physica Status Solidi (b) 211, 39 (1999)

Highpressure cinnabarlike phases in IIIV
compounds
A. Mujica, A. Munoz, S. Radescu, and
R.J. Needs
Physica Status Solidi (b) 211, 345 (1999)
 A quantum Monte Carlo approach to the adiabatic connection
method
M. Nekovee, W.M.C. Foulkes, A.J. Williamson, G
Rajagopal, and R.J. Needs
Advances in Quantum Chemistry
33, 189 (1999)

Dynamic image potential at an Al(111) surface
I.D. White, R.W. Godby, M.M. Rieger, and R.J. Needs
Phys. Rev. Lett. 80, 4265 (1998)

Diffusion quantum Monte Carlo calculations of the excited states
of silicon
A.J. Williamson, R.Q. Hood, R.J. Needs,
and G. Rajagopal
Phys. Rev. B 57, 12140 (1998)

Quantum Monte Carlo calculations of the onebody density matrix
and excitation energies of silicon
P.R.C. Kent,
R.Q. Hood, M.D. Towler, R.J. Needs, and G. Rajagopal
Phys. Rev. B 57, 15293 (1998)

Theoretical study of the cinnabar phases in GaAs and
GaP
A. Mujica, A. Munoz and R.J. Needs
Phys. Rev. B 57, 1344 (1998)

Exchange and correlation in silicon
R.Q. Hood,
M.Y. Chou, A.J. Williamson, G. Rajagopal, and R.J. Needs
Phys. Rev. B
57, 8972 (1998)

Quantum Monte Carlo Simulations of Real Solids
W.M.C. Foulkes, M. Nekovee, R.L. Gaudoin, M.L. Stedman,
R.J. Needs, R.Q. Hood,
G. Rajagopal, M.D. Towler,
P.R.C. Kent, Y. Lee, W.K. Leung, A.R. Porter, and
S.J. Breuer,
"High Performance Computing", edited by
R.J. Allan, M.F. Guest, A.D. Simpson, D.S. Henty,
and
D.A. Nicole (Plenum) 1998

Theoretical study of the high pressure phase stability of GaP,
InP, and InAs
A. Mujica and R.J. Needs
Phys. Rev. B 55, 9659 (1997)

Firstprinciples calculations of the adsorbateinduced surface
stress of K/Al(111) (r3xr3)R30
R.J. Needs and
G. Rajagopal
Surf. Sci. 372, 179 (1997)

Quantum Monte Carlo investigation of exchange and correlation in
Silicon
R.Q. Hood, M.Y. Chou, A.J. Williamson,
G. Rajagopal, R.J. Needs, and W.M.C. Foulkes
Phys. Rev. Lett. 78, 3350 (1997)

Elimination of Coulomb finite size effects in quantum manybody
simulations
A.J. Williamson, G. Rajagopal,
R.J. Needs, L.M. Fraser, W.M.C. Foulkes, Y. Wang, and
M.Y. Chou
Phys. Rev. B
55 (Rapid Communications), 4851 (1997)

Finite size effects and Coulomb interactions in quantum Monte
Carlo calculations for homogeneous systems
with periodic
boundary conditions
L.M. Fraser, W.M.C. Foulkes,
G. Rajagopal, R.J. Needs, S.D. Kenny, and A.J. Williamson
Phys. Rev. B 53, 1814 (1996)
 The Cmcm structure and the high pressure phase stability of
IIIV and IIVI compounds
A. Mujica, A. Munoz, and
R.J. Needs
Proceedings of the 23rd International Conference on
the Physics of Semiconductors, Berlin (1996)

The Cmcm structure as a stable phase of binary compounds:
application to GaAsII
A. Mujica and R.J. Needs
J. Phys.:Condensed Matter 8, L237 (1996)

High pressure phase stability in IIIV and IIVI binary compounds
and the Cmcm phase: a theoretical study
A. Mujica,
R.J. Needs, and A. Munoz
Physica Status Solidi (B)
198, 461 (1996)

Comparison of the calculated and observed Fermi surfaces of
Sr_{2}RuO_{4}
G.J. McMullan,
M.P. Ray, and R.J. Needs
Physica B 223 and 224,
529 (1996)
 Quantum Monte Carlo
studies of electronic systems
R.J. Needs,
G. Rajagopal, A.J. Williamson, L.M. Fraser, S.D. Kenny,
W.M.C. Foulkes, A.J. James, and P. Maccallum
Journal of
Korean Physical Society 29, No.SS, 116 (1996)

Quantum Monte Carlo calculations of the energy of the
relativistic homogeneous electron gas
S.D. Kenny,
G. Rajagopal, R.J. Needs, W.K. Leung, M.J. Godfrey,
A.J. Williamson, and W.M.C. Foulkes
Phys. Rev. Lett. 77, 1099 (1996)

Optimized wavefunctions for quantum Monte Carlo studies of atoms
and solids
A.J. Williamson, S.D. Kenny,
G. Rajagopal, A.J. James, R.J. Needs, L.M. Fraser,
W.M.C. Foulkes, and P. Maccallum
Phys. Rev. B 53, 9640
(1996)

Dynamics of sandpiles: the competing roles of grains and
clusters
A. Mehta, G.C. Barker, J.M. Luck, and
R.J. Needs
Physica A 224, 48 (1996)

Charge transfer excitations in the cuprate superconductors
Z. Dadachanji, R.W. Godby, R.J. Needs, and
P.B. Littlewood
Phys. Rev. B 52, 16204 (1995)

Firstprinciples pseudopotential study of the phase stability of
IIIV semiconductors; GaAs and AlAs
A. Mujica,
R.J. Needs, and A. Munoz
Phys. Rev. B 52, 8881 (1995)

Spinorbit interaction triplet lifetime, and finestructure
splitting of excitons in highly porous silicon
K.J. Nash, P.D.J. Calcott, L.T. Canham, and R.J. Needs
Phys. Rev. B 51, 17698 (1995)

Comment on "MetalCeramic Adhesion and the Harris Functional"
M.W. Finnis, R.J. Needs, and U. Schonberger
Phys. Rev. Lett. (Comments) 74, 3083 (1995)

Firstprinciples pseudopotential study of the structural phases
of silicon
R.J. Needs and A. Mujica
Phys. Rev. B 51, 9652 (1995)

Spacetime method for ab initio calculations of selfenergies and
dielectric response of solids
H.N. Rojas,
R.W. Godby, and R.J. Needs
Phys. Rev. Lett. 74, 1827
(1995)
 GW
selfenergy calculations of carrierinduced band gap narrowing in
ntype silicon
A. Oschlies, R.W. Godby, and
R.J. Needs
Phys. Rev. B 51, 1527 (1995)

Variational and diffusion quantum Monte Carlo calculations at
nonzero wavevectors: theory and application to
diamondstructure germanium
G. Rajagopal,
R.J. Needs, A. James, S. Kenny, and W.M.C. Foulkes
Phys. Rev. B 51, 10591 (1995)

Relativistic corrections to atomic energies from quantum Monte
Carlo calculations
S.D. Kenny, G. Rajagopal, and
R.J. Needs
Phys. Rev. A 51, 1898 (1995)

Firstprinciples study of the electronic properties of silicon
quantum wires
R.J. Needs, A.J. Read, K.J. Nash,
S. Bhattarcharjee, A. Qteish, L.T. Canham, and P.D.J. Calcott
Physica A 207, 411 (1994)
 Theory
of field ionization
S.C. Lam and R.J. Needs
Appl. Surf. Sci. 76/77, 61 (1994)
 Photoluminescence mechanisms in porous silicon
K.J. Nash, P.D.J. Calcott, L.T. Canham, A.G. Cullis, M.J. Kane,
R.J. Needs, S. Bhattacharjee, A.J. Read, and A. Qteish
Proceedings of the 22nd International Conference on the Physics
of Semiconductors, Vancouver (1994)

Abinitio pseudopotential calculations of the valence band offset
at HgTe/CdTe, HgTe/InSb and CdTe/InSb interfaces:
transitivity and orientation dependence
A. Qteish and R.J. Needs
Computational Materials
Science 2, 395 (1994)

Polarization, structural and electronic properties of SiC
polytypes
A. Qteish, R.J. Needs, and V. Heine
Computational Materials Science 2, 389 (1994)

Bandstructure effecs in the dynamic response of aluminium
N.E. Maddocks, R.W. Godby, and R.J. Needs
Europhys. Lett. 27, 681 (1994)

Firstprinciples calculations of bandedge electronic states of
silicon quantum wires
R.J. Needs, S. Bhattacharjee,
K.J. Nash, A. Qteish, A.J. Read, and L.T. Canham
Phys. Rev. B
50, 14223 (1994)

Ab initio calculations of the dynamic response of beryllium
N.E. Maddocks, R.W. Godby, and R.J. Needs
Phys. Rev. B (Rapid Communications) 49, 8502 (1994)

Firstprinciples study of the effects of interface structure on
the Schottky barrier height of the Al/GaAs(110) interface
R.J. Needs, J.P.A. Charlesworth, and R.W. Godby
Europhys. Lett. 25, 31 (1994)

Quantum Monte Carlo calculations for solids using special
kpoints methods
G. Rajagopal, R.J. Needs,
S. Kenny, W.M.C. Foulkes, and A. James
Phys. Rev. Lett. 73, 1959 (1994)

An optimised Ewald method for longranged
potentials
G. Rajagopal and R.J. Needs
J. Comput. Phys. 115, 399 (1994)

Valence band offset transtitivity and interface states at
HgTe/CdTe, HgTe/InSb and CdTe/InSb interfaces
A. Qteish and R.J. Needs
Phys. Rev. B 47, 3714 (1993)

Firstprinciples calculations of manybody bandgap narrowing at
an Al/GaAs(110) interface
J.P.A. Charlesworth,
R.W. Godby, and R.J. Needs
Phys. Rev. Lett. 70, 1685
(1993)

Modelpotential calculations of tunnelling rateconstants for
the fieldion microscope
S.C. Lam and
R.J. Needs
J. Phys.: Condensed Matter 5, 1195 (1993)

Free energy and entropy of diffusion by Ab Initio molecular
dynamics: alkali ions in silicon
V. Milman,
M.C. Payne, V. Heine, R.J. Needs, J.S. Lin, and M.H. Lee
Phys. Rev. Lett. 70, 2928 (1993)

Imaging atoms in the fieldion microscope; tunnelling
calculations using realistic potentials
S.C. Lam
and R.J. Needs
Phys. Rev. B 48, 14698 (1993)

Firstprinciples calculations of the screening of electric
fields at the aluminium (111) and (110) surfaces
S.C. Lam and R.J. Needs
J. Phys.: Condensed Matter 5,
2101 (1993)

Firstprinciples calculations of the structural properties,
stability and band structure of complex tetrahedral phases
of germanium: ST12 and BC8
A. Mujica and
R.J. Needs
Phys. Rev. B 48, 17010 (1993)

Comment on "Should all surfaces be reconstructed ?"
R.J. Needs
Phys. Rev. Lett. (Comments) 71,
460 (1993)
 < Friction in vibrated powders  a mechanism for
memory
A. Mehta and R.J. Needs
Trans. I. Chem. E. 71 A3, 245 (1993)

Structural and electronic properties of SiC
polytypes
A. Qteish, V. Heine, and R.J. Needs
Physica B 185, 366 (1993)
 Dynamics and structural relaxation in powders
A. Mehta, G.C. Barker, and R.J. Needs
In "Powders and Grains
'93'", ed. C. Thornton, (A.A. Balkema, Rotterdam, 1993) p. 233

Energies of atoms and solids within the localdensity
approximation
B. Farid and R.J. Needs
Phys. Rev. B 45, 1067 (1992)

Improved modelsolid theory calculations for valence band
offsets at semiconductorsemiconductor interfaces
A. Qteish and R.J. Needs
Phys. Rev. B 45, 1317 (1992)

Polarization, band lineups and stability of SiC polytypes
A. Qteish, V. Heine, and R.J. Needs
Phys. Rev. B
45, 6534 (1992)
 Theory
of the effects of image potentials on tunnelling in the
fieldion microscope
S.C. Lam and R.J. Needs
Surf. Sci. 271, 376 (1992)

The Langevin dynamics of vibrated powders
A. Mehta,
R.J. Needs, and S. Dattagupta
J. Stat. Phys. 68 5/6,
1131 (1992)

Green's function quantum Monte Carlo study of a jellium
surface
X.P. Li, R.J. Needs, R.M. Martin, and
D.M. Ceperley
Phys. Rev. B 45, 6124 (1992)

Firstprinciples selfenergy calculations of carrierinduced
band gap narrowing in silicon
A. Oschlies,
R.W. Godby, and R.J. Needs
Phys. Rev. B (Rapid
Communications) 45, 13741 (1992)

Electronic charge displacement around a stacking fault boundary
in SiC polytypes
A. Qteish, V. Heine, and
R.J. Needs
Phys. Rev. B 45, 6376 (1992)

Optimized normconserving pseudopotentials
G. Kresse, J. Hafner, and R.J. Needs
J. Phys.: Condensed
Matter 4, 7451 (1992)

Firstprinciples calculations of the electronic properties of
silicon quantum wires
A.J. Read, R.J. Needs,
K.J. Nash, L.T. Canham, P.D.J. Calcott, and A. Qteish
Phys. Rev. Lett. 69, 1232 (1992), Erratum
Phys. Rev. Lett. 70, 2050 (1993)

Calculations of ionization rateconstants in the fieldion
microscope
S.C. Lam and R.J. Needs
Surf. Sci. 277, 359 (1992)

Fieldion microscope tunnelling calculations for the aluminium
(111) and (110) surfaces
S.C. Lam and
R.J. Needs
Surf. Sci. 277, 173 (1992)

A computational study into the origin of SiC
polytypes
V. Heine, C. Cheng, and R.J. Needs
Materials Science and Engineering B 11, 55 (1992)

Electronic excitation energies in Schottky
barriers
J.P.A. Charlesworth, R.W. Godby,
R.J. Needs, and L.J. Sham
Materials Science and Engineering
B 14, 262 (1992)
 The origin of polytypes in SiC and ZnS
V. Heine,
C. Cheng, G.E. Engel, and R.J. Needs
In "Wide BandGap
Semiconductors", ed. T.D. Moustakas, J.I. Pankove and
Y. Hamakawa
MRS Symposium Proceedings Vol. 242, Materials
Research Society, Pittsburgh (1992)

Pseudopotential calculations of the valence band offsets at the
ZnSe/Ge, ZnSe/GaAs and GaAs/Ge (110) interfaces:
effects of
the Ga and Zn 3delectrons
A. Qteish and
R.J. Needs
Phys. Rev. B 43, 4229 (1991)

A statistical theory of entangled lattice polymers
A. Mehta, R.J. Needs, and D.J. Thouless
Europhys. Lett. 14, 113 (1991)

The surface energy and stress of Pb (111) and (110) surfaces
M. Mansfield and R.J. Needs
Phys. Rev. B
43, 8829 (1991)

On the valence band offset controversy in HgTe/CdTe (110)
superlattices
A. Qteish and R.J. Needs
J. Phys.: Condensed Matter 3, 617 (1991)

Calculating optical matrix elements with nonlocal
pseudopotentials
A.J. Read and R.J. Needs
Phys. Rev. B 44, 13071 (1991)

Theory of surface stress and surface reconstruction
R.J. Needs, M.J. Godfrey, and M. Mansfield
Surf. Sci. 242, 215 (1991)
 Total energy calculations and related studies on SiC and ZnS
polytypes
C. Cheng, V. Heine, R.J. Needs, G.E. Engel,
and I.L. Jones
Proceedings of the 20th International
Symposium on Electronic Structure of Solids
ed. P. Ziesche,
Nova Science Publishing Inc., New York, 67 (1991)

The preference of silicon carbide for growth in the metastable
cubic form
V. Heine, C. Cheng, and R.J. Needs
J. Am. Ceram. Soc. 74, 2630 (1991)
 Ab initio static and dynamical simulations: application to
diffusion
V. Milman, M.C. Payne, V. Heine, R.J. Needs,
and J.S. Lin
Proceedings of the APS 1991 Topical Conference
on Shock Compression of Condensed Matter
Williamsburg VA,
USA, ed. S.C. Schmidt, R.D. Dick, J.W. Forbes and D.G. Tasker,
1991
 A
pseudopotential total energy study of impuritypromoted
intergranular embrittlement
L. Goodwin,
R.J. Needs, and V. Heine
J. Phys.: Condensed Matter
2, 351 (1990)

Total energy calculations on zinc sulphide polytypes
G.E. Engel and R.J. Needs
J. Phys.: Condensed
Matter 2, 367 (1990)

Application of the FrenkelKontorova model to surface
reconstructions
M. Mansfield and R.J. Needs
J. Phys.: Condensed Matter 2, 2361 (1990)

Atomic relaxation in silicon carbide polytypes
C. Cheng, V. Heine, and R.J. Needs
J. Phys.: Condensed
Matter 2, 5115 (1990)
 A
new and efficient scheme for firstprinciples calculations of
phonon spectra
R.D. KingSmith and R.J. Needs
J. Phys.: Condensed Matter 2, 3431 (1990)

Calculations of the structural properties of cubic zinc
sulphide
G.E. Engel and R.J. Needs
Phys. Rev. B 41, 7876 (1990)

Calculations of the electronic structure of highly strained
GaAsGaSb heterostructures
A. Qteish and
R.J. Needs
Phys. Rev. B 42, 3044 (1990)

Boundaryboundary interactions and the origin of silicon carbide
polytypes
C. Cheng, V. Heine, and R.J. Needs
Europhys. Lett. 12, 69 (1990)

The surface stress of aluminium and jellium
R.J. Needs and M.J. Godfrey
Phys. Rev. B. 42, 10933
(1990)

Total energy calculations of dimer reconstructions on the
silicon (001) surface
N. Roberts and
R.J. Needs
Surf. Sci. 236, 112 (1990)

Tailoring materials for quantum wells: band offsets at
(001)oriented GaAs/(AlAs)_{n}(GaAs)_{m}
interfaces
K. Karlsson, R.J. Needs, A. Qteish, and
R.W. Godby
J. Phys.: Condensed Matter 2, 5265 (1990)

Band structures for excited state spectroscopies
R.W. Godby and R.J. Needs
Physica Scripta T31, 227
(1990)
 The temperature dependence of the indirect band gap of
silicon: theory and firstprinciples calculation
R.D. KingSmith and R.J. Needs
20th International conference
on the Physics of Semiconductors,
ed. E.M. Anastassakis and
J.D. Joannopoulos, World Scientific, 1755, (1990)
 A manybody approach to calculating groundstate total
energies of semiconductors
B. Farid, R.W. Godby, and
R.J. Needs, 20th International conference on the Physics of
Semiconductors,
ed. E.M. Anastassakis and J.D. Joannopoulos,
World Scientific, 1759, (1990)
 Exchange and correlation in electronic structure
calculations
J.P.A. Charlesworth, A. Oschlies,
R.W. Godby, R.J. Needs, and L.J. Sham
20th International
conference on the Physics of Semiconductors,
ed. E.M. Anastassakis and J.D. Joannopoulos, World Scientific,
1723, (1990)

Exchange and correlation in densityfunctional theory and
quasiparticle theory
R.W. Godby, R.J. Needs, and
B. Farid
Int. J. Quantum Chemistry: Quantum Chemistry
Symposium 24, 681 (1990)

Materials under the mathematical microscope
R.W. Godby, R.J. Needs, and M.C. Payne
Physics
World 3, 39 (1990)

Metalinsulator transition in KohnSham theory and quasiparticle
theory
R.W. Godby and R.J. Needs
Phys. Rev. Lett. 62, 1169 (1989)

Cleavage and shear stresses in impurity promoted
embrittlement
L. Goodwin, R.J. Needs, and
V. Heine
Europhys. Lett. 9, 551 (1989)

Total energy calculations of missing dimer reconstructions on
the silicon (001) surface
N. Roberts and
R.J. Needs
J. Phys.: Condensed Matter
1, 3139 (1989)

Calculations of the surface stress tensor and surface energy of
the (111) surfaces of iridium, platinum and gold
R.J. Needs and M. Mansfield
J. Phys.: Condensed Matter
1, 7555 (1989)

Tests of the Harris energy functional
A.J. Read
and R.J. Needs
J. Phys.: Condensed Matter
1, 7565 (1989)

A firstprinciples calculation of the temperature dependence of
the indirect band gap of silicon
R.D. KingSmith,
R.J. Needs, V. Heine, and M.J. Hodgson
Europhys. Lett. 10, 569 (1989)
 Total
energy and stress of metal and semiconductor
surfaces
M.C. Payne, N. Roberts, R.J. Needs,
M. Needels, and J.D. Joannopoulos
Surf. Sci. 211/212,
1 (1989)

A theory of the origin of SiC polytypes
C. Cheng, R.J. Needs,
V. Heine, and I.L. Jones
Phase Transitions 16/17, 263 (1989)

Interlayer interactions and the origin of SiC polytypes
C. Cheng, R.J. Needs, and V. Heine
J. Phys. C
21, 1049 (1988)

Effect of impurity bonding on grainboundary embrittlement
L. Goodwin, R.J. Needs, and V. Heine
Phys. Rev. Lett. 60, 2050 (1988)

Revised results for the structural properties of arsenic
R.J. Needs and R.M. Martin
Phys. Rev. B
35, 9851 (1987)

Calculations of the surface stress tensor at aluminium (111) and
(110) surfaces
R.J. Needs
Phys. Rev. Lett. 58, 53 (1987)

Confirmation of an ANNNIlike model for polytypism in SiC
C. Cheng, R.J. Needs, V. Heine, and N. Churcher
Europhys. Lett. 3, 475 (1987)

Stability and electronic properties of complex structures of
silicon and carbon under pressure: densityfunctional
calculations
R. Biswas, R.M. Martin, R.J. Needs,
and O.H. Nielsen
Phys. Rev. B 35, 9559 (1987)

The origin and possible implications of surface stress on
metals
R.J. Needs and M.J. Godfrey
Physica
Scripta
T19, 391 (1987)

Totalenergy calculations of the structuralproperties of the
groupV element arsenic
R.J. Needs, R.M. Martin,
and O.H. Nielsen
Phys. Rev. B 33, 3778 (1986)

Theoreticalstudy of the moleculartononmolecular
transformation of nitrogen at high pressures
R.M. Martin and R.J. Needs
Phys. Rev. B 34, 5082
(1986)
 High pressure simple hexagonal phase of silicon
R.J. Needs and R.M. Martin
Proceedings of the 17th
International Conference on the Physics of Semiconductors,
ed. J.D. Chadi and W.A. Harrison, SpringerVerlag (New York),
965 (1985)

Computer simulation of the effect of primitive path length
fluctuations in the reptation model
R.J. Needs
Macromolecules 17, 437 (1984)

Complex tetrahedral structures of silicon and carbon under
pressure
R. Biswas, R.M. Martin, R.J. Needs, and
O.H. Nielsen
Phys. Rev. B 30, 3210 (1984)

Transition from betatin to simple hexagonal silicon under
pressure
R.J. Needs and R.M. Martin
Phys. Rev. B 30, 5390 (1984)

Computer simulation of the dynamics of star molecules
R.J. Needs and S.F. Edwards
Macromolecules
16, 1492 (1983)
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Richard Needs